Johnson said he went to investigate after an alarm went off due to a strong odor of gas in the couple’s apartment. The smell of exhaust prompted Johnson to search further, leading him to the garage.

“Basically she died because of carbon monoxide,” Johnson said. “They do not have adequate alarm systems, because if there had been an alarm in that garage, people would have been alerted to the fact that it was going on.”

“As I tried to step to open the last garage door, I see the mechanic, he’s laid out,” Johnson said in an interview with WABC. “She’s just a few feet away, she’s laid out. And pretty much I had to call 911 because, at this time, with that level of emissions, I knew that they were gone.”

Authorities believe their deaths were accidental.

“Basically she died because of carbon monoxide,” Johnson said. “They do not have adequate alarm systems, because if there had been an alarm in that garage, people would have been alerted to the fact that it was going on.”